AB0505 RISK OF SYSTEMIC LUPUS ERYTHEMATOSUS FLARES ACCORDING TO THE POSITIVITY OF AUTOANTIBODIES
Authors: O. C. Kwon, M. C. Park
Journal: Annals of the Rheumatic Diseases (2022)

Background Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by excessive production of pathogenic autoantibodies. A variety of autoantibodies can be detected in patients with SLE. Presence of particular autoantibody is known to be associated with specific manifestations of SLE: anti-double-stranded DNA antibody (anti-dsDNA Ab) with renal involvement and overall disease activity, anti-Sm Ab with renal involvement, anti-Ro Ab with cutaneous lupus and neonatal lupus, anti-La Ab with cutaneous lupus and neonatal lupus, and anti-U1RNP Ab with Raynaud’s phenomenon and pulmonary hypertension. However, little is known about the association between positivity of each autoantibody and risk of SLE flare. Objectives We aimed to assess the risk of SLE flare according to the positivity of various autoantibodies. Methods A total of 228 patients with SLE who fulfilled the 2012 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria for SLE were included. SLE flare was defined as an increase of SLE disease activity index-2000 (SLEDAI-2K) of more than 4 points and/or hospitalization for SLE and/or augmentation of SLE therapy. The occurrence of flare was retrospectively reviewed from the date of SLE diagnosis to the date of last follow-up. Multivariable Cox regression analysis was conducted to estimate the hazard ratio (HR) and 95% confidence interval (CI) of SLE flare, according to the positivity of autoantibodies. Multivariable model was adjusted for sex, age at SLE diagnosis, positivity of other autoantibodies, SLEDAI-2K at diagnosis, use of immunosuppressants. Results Among the 228 patients, flare occurred in 179 (78.5 %) patients during 635.0 person-years of follow-up (incidence rate: 28.2/100 person-years). Of the 179 flares, 92 were severe flares (necessitating use of glucocorticoid dose &gt; 20mg of prednisolone or equivalent, and/or addition of immunusuppressants), whereas 87 were mild-to-moderate flares (necessitating use of glucocorticoid dose &lt; 20mg of prednisolone or equivalent, and no addition of immunosuppressants). In the multivariable Cox regression analysis, anti-dsDNA Ab positivity (adjusted HR 1.46, 95% CI 1.04–2.05, p = 0.031) and anti-Sm antibody positivity (adjusted HR 1.73, 95% CI 1.16–2.59, p = 0.007) were significantly associated with a higher risk of SLE flares. Conclusion Patients with SLE who are positive for anti-dsDNA Ab or anti-Sm Ab at diagnosis have a higher risk of SLE flare during the course of their disease. Careful monitoring of disease activity and prompt adjustment of therapy accordingly could be helpful in these patients. References Not applicable. Table 1. Risk of flares according to the positivity of each autoantibodies Univariable analysis Multivariable analysis a Unadjusted HR (95% CI) P value Adjusted HR (95% CI) P value Anti-dsDNA antibody positivity 1.47 (1.09–1.99) 0.011 1.46 (1.04–2.05) 0.031 Anti-Sm antibody positivity 1.52 (1.12–2.07) 0.008 1.73 (1.16–2.59) 0.007 Anti-Ro antibody positivity 1.19 (0.88–1.61) 0.252 1.04 (0.71–1.52) 0.836 Anti-La antibody positivity 1.24 (0.89–1.74) 0.211 1.26 (0.83–1.92) 0.278 Anti-U1RNP antibody positivity 1.19 (0.89–1.60) 0.250 0.83 (0.57–1.21) 0.332 a Adjusted for sex, age at diagnosis, positivity of other autoantibodies, SLEDAI-2K at diagnosis, use of immunosuppressants Acknowledgements None. Disclosure of Interests None declared